The following paragraphs are not an admission that anything discussed in them is prior art or part of the knowledge of persons skilled in the art.
U.S. Pat. No. 6,604,327 (Reville) discloses a retractable trackless spa enclosure including at least two sections, a first section being slightly smaller than a second section.
U.S. Pat. No. 4,175,361 (Kumode) discloses an openable canopy housing having a series of movable, telescoping, transparent and arched panels which form the combination roof and sides.
U.S. Pat. No. 6,637,160 (Brooks) discloses a plurality of movable transparent arcuate sections that can roll on their own designated tracks to enclose or expose a sun room or pool area.
U.S. Pat. No. 5,907,928 (Charbonnel) discloses a removable protective shelter.
U.S. Pat. No. 5,373,668 (Shulman) discloses a cottage with a rear framed section that is adjacent to a front framed section, wherein the cottage functions to position the roof completely over the rear framed section or the front framed section, and in positions therebetween.
U.S. Patent Publication No. 20060254160 (Lee) discloses a telescopic shelter system comprising two pairs of guide rails having a pair of parallel outer rails and a pair of parallel inner rails arranged at an inner side of the outer rails, a plural of shelters comprising two side walls facing each other and a roof connecting at the top of the two side walls.